et_al at my-deja.com wrote:
> On 7 Feb 2002 13:51:41 GMT, dag.stenberg at nospam.helsinki.fi wrote:
>>et_al at my-deja.com wrote:
>>> SSRIs don't actually increase serotonin levels.
>>Yes, they do, provided that inhibitory autoreceptors are downregulated...
>>> Hmmm. These, among others, seem not to agree:
> :: ................
I agree that the question of what happens in the serotonin synapses
during SSRI treatment with or without autoreceptor blocking is not easy
to answer, and different experimental approaches yield somewhat
different results. (Some of the papers you cited addressed total (store +
release) 5HT levels; I think the focus has to be put on release and
extracellular concentrations).
I think one might sagree that in the majority of situations, acute
administration of SSRIs will not increase synaptic 5HT levels, and they
will tend to decrease 5HT production. However, it is possible to devise
situations where synaptic levels are increased. I have seen some of
these results presented, and they make sense. There is disagreement
over whether this is presently reliably feasible in patients, and how it
relates to the antidepressive effect. I think my main point is that we
are not ready to discard the serotonin hypothesis of mood improvement.
In all, I think that the question of how antidepressants affect
serotonin release is interesting because of its importance and its
complexity. Sadly, I do not have the resources to go for this research,
so my reading is a bit sloppy also. I was aware of the various
disagreements, though. (By the way, who is good at measuring tryphophan
hydroxylase mRNA?)
Dag Stenberg